热轧带钢层流冷却中的温度演变及返红规律

:2005205224:(G2000067208-4):(1978-),,,;(1953-),,,,;(1942-),,,,,27420064()JournalofNortheasternUniversity(NaturalScience)Vol127,No.4Apr.2006:100523026(2006)0420410204,,(,110004):,1/3;;();:;;;;;:TG335.15:A,,[15],2050mm,,,,11.1,[6](1):9T9t=kcp92T9x2+92T9y2(1),T,K;t,s;k,W/(mK);,kg/m3;cp,J/(kgK);xy,m1.2,,,,,5091.3T0(x,y,0)[7][7,8],:hw=917210501355Ts-Tw(215-115logTw)DP1Pc0165411263(2),hw,W/(m2K);,m3/(minm2);D,m;Ts,Tw,K;P1,Pc,m[9],:hr=s(T2s+T2)(Ts+T),hd=2115(Ts-T)0125,hj=hr+hc(3),hr,W/(m2K);hd,W/(m2K);hj,W/(m2K);SStefan2Boltzman,W/(m2K4);;Ts,K;T,K22.12050mm,VisualC++6.0FEM,1k[10]1;7850kg/m3;cp212050mmFig.1LayoutschematicoflaminarcoolinglineinB2steel1kTable1Heatconductioncoefficientofstrip,k/5010020040050060070080010001200k/(Wm-1K-1)51.550.548.642.739.335.631.925.927.729.82cpTable2Specificheatofstrip,cp/50100100150150200350400450500550600650700750800950100011501200cp/(Jkg-1K-1)4865025195956627458469556456622.2416mm,85322Fig.2Temperaturedropofstripinlaminarcoolingprocess2,,,,,3,,,,1602.3,,4a,b,c,5,,,1144:,3()Fig.3Temperaturedistributionbeforeandafterlaminarcooling(a);(b)41/4Fig.4Schematicoftypicalnodepointsinstripsectionalareasection51/4Fig.5Coolingrateoftypicalnodepointsin1/4stripsectionalarea(a)a;(b)b;(c)c5a,,,,;5b,5c,,:,,;,,,,1/3(01767mm),6,,()61/4Fig.6Positionofcriticallinein1/4stripsectionalarea,01616s(01767mm),,(),7=1712793+4614769t-4612589t2-4210789h+1219003h2(5),,;t,s,(0t01616s);h,mm,(0h01767mm)214()277Fig.7Variationofre2reddeningtemperaturewithtimeanddistancefromstripsurface01993698,1113,01017,,;,,,3(1),,(2),,,(3),()(4),:[1]ShaXC,LiDZ,LanYJ,etal.Modellingthetemperaturedistributionalongthelengthofstripduringhotrollingprocess[J].SteelResearchInternational,2004,75(5):330-338.[2]JamesF,RoebuckLE,HowardD,etal.Numericalmodelingofhotstripmillrunouttablecooling[J].IronandSteelEngineer,1993,70(1):50.[3]LanYJ,LiDZ,ShaXC,etal.Predictionofmicrostructureandmechanicalpropertiesofhotrolledsteelstrip:PartIdescriptionofmodels[J].SteelResearchInternational,2004,75(7):462-467.[4]LaberK,DyjaH,RydzD.Analyticalandnumericalmethodsofdeterminingthedistributionoftemperatureofair2cooledstrip[J].Metalurgija,2005,44(1):31-35.[5]IshiokaM.Basicstudyoncontrolledcoolingprocessofplate[J].CAMP2ISIJ,1994,7:404-407.[6][M]:,1998.1-2(KongXQ.Applicationoftheelementmethodinheattransfer[M]Beijing:SciencePress,1998.1-2.)[7],,[J],1998,33(8):69-72(CaiZ,WangGD,LiuXH.Modelofhotrolledstriptemperaturedistributionduringlaminarcooling[J].IronandSteel,1998,33(8):69-72).[8]HattaN,OsakabeH.Numericalmodelingforcoolingprocessofamovinghotplatebyalaminarwatercurtain[J].ISIJInternational,1989,29:919.[9],,,[J](),2000,21(4):427-430(LiCS,HeXM,LiuXH,etal.Finiteelementanalysisfortemperaturefieldofthesolidslabduringair2cooling[J].JournalofNortheasternUniversity(NaturalScience),2000,21(4):427-430.)[10][M],,,:,1990.195-196(InstituteofIronandSteelinJapan.Theoryandpracticeofsteelrolling[M].TranslatedbyWangGD,WuGL,BiYW,etal.Beijing:ChineseRailwayPress,1990.195-196.)TemperatureEvolutionandRe2ReddeningBehaviorofHotRolledStripDuringLaminarCoolingZHIYing,LIUXiang2hua,WANGGuo2dong(TheStateKeyLaboratoryofRolling&Automation,NortheasternUniversity,Shenyang110004,China.Correspondent:ZHIYing,E2mail:[e-mail])Abstract:Analyzesthetemperaturefieldofhotrolledstripduringlaminarcoolingbyfiniteelementmethod,andcalculatesthecoolingrateattypicalpositionstoinvestigatehowthecoolingratevarieaperiodicallyduringwatercoolingandsubsequentre2reddening.Itisfoundthatthereisacriticallineofcoolingrateatthepositionthatissectionally1/3half2thicknessawayfromthestripsurface,andthecoolingratevariesalternatelybetweenpositiveandnegativevaluesbetweenthesurfaceandthecriticalline.Itimpliesthatthecriticallineisinfactademarcationlinebetweenthetransientheatoutputzoneandinputzone(re2reddeningzone)incoolingprocess.Aregressionmodelfortherelationshipamongre2reddeningtemperature,timeanddistancesfromdifferentnodepointstothesurfaceisthusobtainedinre2reddeningzone.Theresultscanbeusedasreferenceforthepredictionandcontrolofmicrostructuresandpropertiesofstripsinrollingprocess.Keywords:temperaturefield;re2reddening;laminarcooling;coolingrate;hotrolledstrip;finiteelementmethod(ReceivedMay24,2005)3144: